Method of finishing nylon textile material



United States Patent 3,197,270 METHOD OF FINISHING NYLON TEXTILE MATERIAL Philip B. Roth, Bridgewater Township, Somerset County,

N..l., assignor to American Cyanamid Company, Stamford, Conn, a corporation of Maine No Drawing. Filed Nov. 1, 1962, Ser. No. 234,876

7 Claims. (Cl. 8-115.5)

This invention relates to a new method of finishing nylon textile material and to the textile material so finished. More particularly, this invention relates to a new method of finishing nylon textile material whereby the material is rendered resistant to degradation from sunlight and outdoor weathering as well as heat and moisture. Further, the invention relates to nylon textile material which is resistant to sunlight and weathering degradation as well as degradation resulting from exposure to heat and moisture.

It is known that nylon textile material, when subjected to extensive sunlight and weathering, becomes brittle due to the crystallization of the nylon or polyamide. This crystallization results in poor tensile strength, which more often than not is accompanied by a decline in the appearance of the material.

There are many solutions presently being employed for the purpose of eliminating or minimizing the degradation of nylon which results from exposure to sunlight and outdoor weathering conditions. lllustratively, ultraviolet light absorbing materials have been employed with nylon. However, the application of such materials to formed nylon fabricsnormally requires application from solvent solutions which require processing conditions and equipment which some finishing mills do not have. Such mills are, of course, unable to employ such processes. Some ultraviolet absorbing materials are toxic in nature or have the deficiency that they discolor the nylon textile material, adversely affect its hand, or have poor durability to laundering or dry cleaning. Still in other known processes ultraviolet light absorbing materials are applied to nylon fabrics employing conventional textile finishing procedures which require the application or employment of heat in order to render the finish durable. In many instances, the application of heat required produces discoloration in the fabric along with a stiffening and harshening of the hand of the material. It will be apparent that temperature control must be employed in that if the temperature is permitted to rise above the melting point of nylon, fusion may result.

In addition to the above, it is also known that when nylon textile materials are exposed to heat and/or moisture that the materials are rapidly degraded. This degradation, as in the case of materials exposed to sunlight and repeated weathering, manifests itself through the discoloration of the nylon material and its loss in tensile strength. I

Fabrics of nylon find many applications where they are repeatedly subjected to heat and moisture. One environment where nylon fabrics are subjected to what might be called severe conditions of exposure to heat and moisture is in laundries and dry cleaning establishments, where ironing machines and steam presses are used routinely, and where nylon cover cloths employed therewith arerepeatedly exposed to steam and temperatures up to 250 F. Such cover cloths become discolored and tendered from such exposure and must be replaced frequently.

The replacement of these cover pads or cloths is time consuming and requires shutting down the iron or press. Any processing of these cloths which would minimize 3,197,279 Patented July 27, 1965 "ice shut-down time, and which would significantly cut replacement costs, would be of considerable value.

Accordingly it is an object of the present invention to provide a process for finishing nylon textile material whereby the material is rendered resistant to degradation from sunlight and outdoor weathering and in addition is rendered resistant to degradation resulting from the application of heat and/ or moisture.

A further object of the present invention is to provide nylon textile material characterized by a resistance to degradation from sunlight and outdoor exposure as well as from exposure to heat and/or moisture.

It is a further object of the present invention to provide a method for improving the resistance to degradation of nylon textile materials from sunlight, outdoor exposure and heat and moisture which does not affect the hand adversely, i.e., does not harshen the hand, is durable to laundering and dry cleaning, does not discolor the material, and is capable of application in a simple straightforward procedure which does not require the use of solvents and solvent recovery apparatus.

These and other objects and advantages of the present invention will become more apparent from the detailed description thereof set forth hereinbelow.

According to the present invention, a method is provided for finishing nylon textile material which comprises applying thereto a water-soluble condensate of melamine and formaldehyde in the presence of a curing catalyst therefor and thereafter durably fixing the melamine-formaldehyde condensate by curing the material so treated while in a wet state and in a closed or sealed container.

By the term nylon as it is employed herein it is meant any of the long-chain synthetic polyamides having recuring amide groups as an integral part of the polymer chain and which is capable of being formed into filaments.

By the term nylon textile material as that term is employed herein it is meant fibers, yarns and fabrics, whether they be knitted, woven, felted or otherwise formed, composed of a major portion of fibers of nylon. Preferably, the nylon textile materials of this invention will consist substantially completely of nylon fibers, though blends of such fibers with non-nylon materials such as cellulosic materials, polyester fibers, acrylic fibers, are contemplated. Such materials will normally contain at least 50%. of nylon fiber.

By the expression water-soluble condensates of melamine and formaldehyde, as that term is employed herein, it is intended to include methylol melamines or c0n densates of melamine and formaldehyde or their alkylated or etherified derivatives such as the methylated methylol melamines. These melamine-formaldehyde condensates are substantially monomeric, though dimeric or trimeric and even low order polymeric material may be present but not to an extent as will adversely affect their solubility in water. The melamine-formaldehyde condensates might include monomethylol melamine, dimethylol melamine and trimethylol melamine.

The alkylated or etherified methylol melamines are prepared by condensing melamine and formaldehyde and subsequently reacting the methylol compound with a suitable alcohol, which canbe one of a number of materials suited for etherification. Illustratively such alcohols include the saturated aliphatic alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol and the like; glycols such as ethylene glycol; glycol ethers and other alcoholic compounds capable of condensing with methylol groups present on the methylolated melamine to form water-soluble reaction products. Methyl alcohol is the preferred alkylating material. Examples of suitable alkylated methylol melamines include bis(methoxymethyl) methylol melamine, tris(methoxymethyl) dimethylol melamine, hexabis(methoxymethyl)-melamine.

The melamine-formaldehyde condensates are applied to the nylon textile material in amounts of from about 2 to about 50% based on the dry weight of the nylon textile material and preferably are employed in amounts of from about 5% to about solids based on the dry weight of the material.

The catalysts employable in the present invention may be those catalysts normally employed in the conventional finishing of cellulosic textile materials with aminoplast to impart a crease resistant textile finish. Thus, the acid saltsof alkanolamines, free acids, including the mineral acids such as hydrochloric, sulfuric and the like, or their corresponding ammonium salts may be employed. Preferably, the catalyst is a metal salt and more specifically a salt of aluminum, such as aluminum chloride, aluminum sulfate and aluminum nitrate. The catalysts are normally employed in amounts of from about 0.25% based on the weight of the resin up to about 15%, based on the weight of the resin, with the preferred amounts being from between about .5 and about 2.5% of catalyst.

The melamine-formaldehyde condensate and the catalyst therefor may be applied in accordance with standard textile finishing procedures, as for example by padding, spraying, dipping, immersing and the like.

After application the finished material is folded or wound on a beam, dowel, rod or other support means and placed in a sealed container such as in a closed bag, tube or the like of flexible air-tight material such as polyethylene films so as to prevent any drying out effect, and the so-wrapped material is then subjected to storage for various periods of time depending upon the type of storage and temperature used in storage. The reaction of the melamine-formaldehyde condensate with the nylon may take place at room temperature or at elevated temperatures, the time of storage for the most part being dependent Upon the temperature at which cure is carried out.

Textile material so treated is preferably cured at low temperature, by which term is meant a temperature of from between ambient or room temperature up to about 200 F. While higher temperatures may be employed, as for example temperatures up to 350 F., the use of such high temperatures is not necessary to obtain the nylon material of improved properties contemplated by this invention. Obviously, temperatures which will degrade nylon should not be employed.

The curing, as noted, is carried out in a sealed container, by which term as it is employed herein it is meant any container such as a closed, preferably airtight room, a bag, illustratively of polyethylene or other flexible film types of materials, which are used to enclose treated materials being cured so as to prevent any drying out effect of the material during the cure. The container should preferably be air-tight.

When the cure has been completed, the finished textile material may be rinsed if it is to receive after-treatment with other finishing agents such as water repellents, fire retardants, softeners and the like and thereafter is normally dried at elevated temperatures.

While, as noted hereinabove, various accelerators may be employed in carrying out the present invention, nonalkylated melamine-formaldehyde condensates may not be employed with metal salts such as the aluminum salts identified above since the pad bath stability of such mixtures is extremely limited. Thus, the addition of salts such as aluminum chloride to dimethylol melamine results in the pad bath setting up substantially immediately.

The present invention has particular application to such nylon textile materials as are employed in rain- Swatches of nylon taffeta were treated with aqueous solutions whereby 10% or 20% solids on the dry weight of the fabric of tris(methoxymethyl)melamine in combination with 1.0% solids anhydrous aluminum chloride (based on the melamine resin solids) were applied by conventional padding. The separate padded swatches were rolled onto glass rods and placed in a polyethylene bag and sealed. The enclosed swatches were then stored for 24 hours at room temperature. After the storage period the swatches were removed, rinsed in clear, room temperature water and dried on a pin tenter frame for 1 minute at 225 F.

Portion of each dried sample and a piece of untreated fabric were tested for warp tensile by the strip method using a Scott Tensile Tester (ASTM method) and the results recorded as Initial.

Other portions of the treated and untreated materials were subjected to outdoor weathering tests. This test consisted of the following:

The nylon textile material was taped onto glass plates and placed outdoors on an uncovered rack at a 45 angle facing upward in a southerly direction. The attached samples were exposed to either one or two months exposure whereby all conditions existed. The swatches after weathering were tested for tensile strength as aforementioned.

Results of tensile tests are shown in Table I. It can be seen that the treatments employed minimized the tensile loss over that of the untreated after two months exposure.

Table 1 Strip Tensile Strength (in lbs.) Warp Only After Outdoor Exposure Percent Strength retained after 2 months exposure (based on initial untreated) Treatment of Fabric Initial lMonth 2Montl1s Untreated A=10% solids tris(metlioxymethyl)melamine plus 1% AlCl3. B=20% solids tris(methoxymethybmelamine plus 1% AlCh.

Table I hereinabove demonstrates that employment of the process of this invention results in a substantial improvement in the strip tensile strength of nylon finished in accordance with this invention as compared with untreated nylon.

EXAMPLE 2 Swatches of nylon taffeta were treated by the four following procedures for comparison purposes:

A. 10% solids on the dry Weight of the fabric tris(methoxymethyl)melamine plus 1% anhydrous AlCl based on resin solids. Wet cured for 24 hours at room temperature.

B. 10% solids on the dry weight of the fabric tris(methoxymethyDmelamine plus 1% anhydrous AlCl based on resin solids. Wet cured for 2 /2 hours at 210 F.

C. 10% solids on the dry weight of the fabric tris(methoxymethyl)melamine plus 1% H01 (37%) based on resin solids. Wet cured for 24 hours at room temperature.

D. solids on the dry weight of the fabric dimethylol melamine plus 10% diacetin based on resin solids. Wet cured for 24 hours at room temperature.

The swatches after treatment were wound on glass rods and placed in individual polyethylene bags and stored for their respective cure times. After curing, the swatches were removed, rinsed and dried by the procedure of Example l.

Portions of the samples were tested for warp strip tensile strength and recorded as initial. Other portions were subjected to outdoor weathering as described in EX- ample 1, and tensile tests were performed after 2 and 6 weeks of weathering. Results are shown in Table H.

Results show that all treatments improved the tensile strengths over that of the untreated after 6 weeks of outdoor exposure.

Table II hereinabove demonstrates that a wide variety of catalytic agents may be employed in the process of this invention for the finishing of nylon and that each produces improved results with respect to tensile strength relative to untreated nylon.

EXAMPLE 3 A nylon cover cloth was finished employing the bath and treatment indicated below.

Treatment00mpounds Used Percent in Bath Bis(methoxymethyl)methylol melamine 30. 0 Aluminum chloride 0. 8 Nonyl phenol plus ethylene oxide O. 1 Water to make 100 Expressi 67 Percent solids (OWF) 16 The nylon fabric was immersed in the bath and run through a three-roll microset padder giving the wet pickup or expression indicated.

The thus treated fabric was folded and enclosed in a polyethylene film, then stored for 24 hours at room temperature (approx. 70 F.) after which it was removed, rinsed in tap water and dried at 225 F.

The nylon cover cloth was submitted to a commercial laundry and was used in the normal manner of pressing and steaming. Comparison was made with a cover which had not been so treated.

Results are shown in Table III.

Table III [CONDITION AND COLOR OF COTTON OR NYLON AFTER 2 MONTHS USE ON PRESSING MACHINES] 1 Still in use after 2 months.

Table III hereinabove demonstrates the surprising improvement which results from the employment of the present process on nylon textile material subjected to extremes in temperature and moisture.

I claim:

1. A method for finishing nylon textile material containing at least 50% by weight of nylon to improve its resistance to degradation from sunlight, weathering, heat and moisture, which comprises applying thereto a watersoluble condensate of melamine and formaldehyde in the presence of a catalytically effective amount of a curing catalyst, durably fixing the condensate of melamine and formaldehyde by effecting complete cure of said condensate on the material so treated while it is in the wet state in a sealed container and at a temperature of from room temperature up to the temperature at which the nylon textile material degrades.

2. A method according to claim 1 in which the condensate of melamine and formaldehyde is applied in amounts of from about 2 to 25% based on the dry weight of the textile material.

3. A method according to claim 1 in which the condensate of melamine and formaldehyde is applied in amounts of from about 5 to 20% based on the dry weight of the textile material.

4. A method according to claim 1 in which the condensate of melamine and formaldehyde is a methylated methylol melamine and the catalyst is selected from the group consisting of aluminum chloride, aluminum sulfate and aluminum nitrate.

5. A method according to claim 1 in which the cure is carried out at a temperature of from room temperature up to about 200 F.

6. Nylon finished according to the process of claim 1.

7. A method for finishing nylon textile material containing at least 50% by weight of nylon to improve its resistance to degradation from sunlight, weathering, heat and moisture, which comprises applying thereto from about 2 to 50%, based on the dry weight of the material, of a water soluble etherified melamine-formaldehyde condensate and from about .25 to about 15%, based on the weight of said condensate, of a curing catalyst, said oatalyst being selected from the group consisting of alumi num chloride, aluminum sulfate, and aluminum nitrate, durably fixing the melamine-formaldehyde condensate by effecting complete cure of said condensate on the material so treated while it is in a wet state in a sealed container and at a temperature of from room temperature up to the temperature at which the material degrades.

References Cited by the Examiner UNITED STATES PATENTS 2,709,141 5/55 Burks 8--1l6.3 3,050,419 8/62 Ruperti 8116.3 X 3,052,570 9/ 62 Polansky 117139.4 3,084,071 4/63 Van Loo 117139.4

NORMAN G. TORCHIN, Primary Examiner.

ABRAHAM H. WINKELSTEIN, Examiner. 

1. A METHOD FOR FINISHING NYLON TEXTILE MATERIAL CONTAINING AT LEAST 50% BY WEIGHT OF NYLON TO IMPROVE ITS RESISTANCE TO DEGRADATION FROM SUNLIGHT, WEATHERING, HEAT AND MOISTURE, WHICH COMPRISES APPLYING THERETO A WATERSOLUBLE CONDENSATE OF MELAMINE AND FORMALDEHYDE IN THE PRESENCE OF A CATALYTICALLY EFFECTIVE AMOUNT OF A CURING CATALYST, DURABLY FIXING THE CONDENSATE OF MELAMINE AND FORMALDEHYDE BY EFFECTING COMPLETE CURE OF SAID CONDENSATE ON THE MATERIAL SO TREATED WHILE IT IS IN THE WET STATE IN A SEALED CONTAINER AND AT A TEMPERATURE OF FROM ROOM TEMPERATURE UP TO THE TEMPERATURE AT WHICH THE NYLON TEXTILE MATERIAL DEGRADES. 